Almost all natural diamonds are impure and contain substitutional nitrogen. Clusters of N atoms are present in Type 1a diamonds (the most common defect structure), while Type 1b diamonds contain….
explain why and how these variables influence the force.
Make a list of the independent variables that influence the punch force in deep drawing of a cylindrical cup, and explain why and how these variables influence the force.
The independent variables are listed at the beginning of Section 7.6.2. The student should be
able to explain why each variable influences the punch force, based upon a careful reading of the
materials presented. The following are sample answers, but should not be considered the only acceptable ones.
(a) The blank diameter affects the force because the larger the diameter, the
greater the circumference, and therefore the greater the volume of material to be deformed.
(b) The clearance, c, between the punch and die directly affects the force; the smaller
the clearance the greater the thickness reduction and hence the work involved.
(c) The workpiece properties of yield strength and strain-hardening exponent affect the
force because as these increase, greater forces will be required to cause deformation
beyond yielding. (d) Blank thickness also increases the volume deformed, and therefore increases the force.
(e) The blankholder force and friction affect the punch force because they restrict the
flow of the material into the die, hence additional energy has to be supplied to overcome